btr0pcur.ic

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

/******************************************************
The index tree persistent cursor

(c) 1996 Innobase Oy

Created 2/23/1996 Heikki Tuuri
*******************************************************/


/*************************************************************
Gets the rel_pos field for a cursor whose position has been stored. */
UNIV_INLINE
ulint
btr_pcur_get_rel_pos(
/*=================*/
				/* out: BTR_PCUR_ON, ... */
	btr_pcur_t*	cursor)	/* in: persistent cursor */
{
	ut_ad(cursor);
	ut_ad(cursor->old_rec);
	ut_ad(cursor->old_stored == BTR_PCUR_OLD_STORED);
	ut_ad(cursor->pos_state == BTR_PCUR_WAS_POSITIONED
			|| cursor->pos_state == BTR_PCUR_IS_POSITIONED);

	return(cursor->rel_pos);
}

/*************************************************************
Sets the mtr field for a pcur. */
UNIV_INLINE
void
btr_pcur_set_mtr(
/*=============*/
	btr_pcur_t*	cursor,	/* in: persistent cursor */
	mtr_t*		mtr)	/* in, own: mtr */
{
	ut_ad(cursor);

	cursor->mtr = mtr;
}

/*************************************************************
Gets the mtr field for a pcur. */
UNIV_INLINE
mtr_t*
btr_pcur_get_mtr(
/*=============*/
				/* out: mtr */
	btr_pcur_t*	cursor)	/* in: persistent cursor */
{
	ut_ad(cursor);

	return(cursor->mtr);
}

/*************************************************************
Returns the btr cursor component of a persistent cursor. */
UNIV_INLINE
btr_cur_t*
btr_pcur_get_btr_cur(
/*=================*/
				/* out: pointer to btr cursor component */
	btr_pcur_t*	cursor)	/* in: persistent cursor */
{
	return(&(cursor->btr_cur));
}

/*************************************************************
Returns the page cursor component of a persistent cursor. */
UNIV_INLINE
page_cur_t*
btr_pcur_get_page_cur(
/*==================*/
				/* out: pointer to page cursor component */
	btr_pcur_t*	cursor)	/* in: persistent cursor */
{
	return(btr_cur_get_page_cur(&(cursor->btr_cur)));
}

/*************************************************************
Returns the page of a persistent cursor. */
UNIV_INLINE
page_t*
btr_pcur_get_page(
/*==============*/
				/* out: pointer to the page */
	btr_pcur_t*	cursor)	/* in: persistent cursor */
{
	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);

	return(page_cur_get_page(btr_pcur_get_page_cur(cursor)));
}

/*************************************************************
Returns the record of a persistent cursor. */
UNIV_INLINE
rec_t*
btr_pcur_get_rec(
/*=============*/
				/* out: pointer to the record */
	btr_pcur_t*	cursor)	/* in: persistent cursor */
{
	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
	
	return(page_cur_get_rec(btr_pcur_get_page_cur(cursor)));
}

/******************************************************************
Gets the up_match value for a pcur after a search. */
UNIV_INLINE
ulint
btr_pcur_get_up_match(
/*==================*/
				/* out: number of matched fields at the cursor
				or to the right if search mode was PAGE_CUR_GE,
				otherwise undefined */
	btr_pcur_t*	cursor) /* in: memory buffer for persistent cursor */
{
	btr_cur_t*	btr_cursor;

	ut_ad((cursor->pos_state == BTR_PCUR_WAS_POSITIONED)
			|| (cursor->pos_state == BTR_PCUR_IS_POSITIONED));

	btr_cursor = btr_pcur_get_btr_cur(cursor);

	ut_ad(btr_cursor->up_match != ULINT_UNDEFINED);

	return(btr_cursor->up_match);
}

/******************************************************************
Gets the low_match value for a pcur after a search. */
UNIV_INLINE
ulint
btr_pcur_get_low_match(
/*===================*/
				/* out: number of matched fields at the cursor
				or to the right if search mode was PAGE_CUR_LE,
				otherwise undefined */
	btr_pcur_t*	cursor) /* in: memory buffer for persistent cursor */
{
	btr_cur_t*	btr_cursor;

	ut_ad((cursor->pos_state == BTR_PCUR_WAS_POSITIONED)
			|| (cursor->pos_state == BTR_PCUR_IS_POSITIONED));

	btr_cursor = btr_pcur_get_btr_cur(cursor);
	ut_ad(btr_cursor->low_match != ULINT_UNDEFINED);

	return(btr_cursor->low_match);
}

/*************************************************************
Checks if the persistent cursor is after the last user record on 
a page. */
UNIV_INLINE
ibool
btr_pcur_is_after_last_on_page(
/*===========================*/
	btr_pcur_t*	cursor,	/* in: persistent cursor */
	mtr_t*		mtr)	/* in: mtr */
{
	UT_NOT_USED(mtr);
	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
	
	return(page_cur_is_after_last(btr_pcur_get_page_cur(cursor)));
}

/*************************************************************
Checks if the persistent cursor is before the first user record on 
a page. */
UNIV_INLINE
ibool
btr_pcur_is_before_first_on_page(
/*=============================*/
	btr_pcur_t*	cursor,	/* in: persistent cursor */
	mtr_t*		mtr)	/* in: mtr */
{
	UT_NOT_USED(mtr);
	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
	
	return(page_cur_is_before_first(btr_pcur_get_page_cur(cursor)));
}

/*************************************************************
Checks if the persistent cursor is on a user record. */
UNIV_INLINE
ibool
btr_pcur_is_on_user_rec(
/*====================*/
	btr_pcur_t*	cursor,	/* in: persistent cursor */
	mtr_t*		mtr)	/* in: mtr */
{
	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
	
	if ((btr_pcur_is_before_first_on_page(cursor, mtr))
	    || (btr_pcur_is_after_last_on_page(cursor, mtr))) {

		return(FALSE);
	}

	return(TRUE);
}

/*************************************************************
Checks if the persistent cursor is before the first user record in
the index tree. */
UNIV_INLINE
ibool
btr_pcur_is_before_first_in_tree(
/*=============================*/
	btr_pcur_t*	cursor,	/* in: persistent cursor */
	mtr_t*		mtr)	/* in: mtr */
{
	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
	
	if (btr_page_get_prev(btr_pcur_get_page(cursor), mtr) != FIL_NULL) {

		return(FALSE);
	}

	return(page_cur_is_before_first(btr_pcur_get_page_cur(cursor)));
}

/*************************************************************
Checks if the persistent cursor is after the last user record in
the index tree. */
UNIV_INLINE
ibool
btr_pcur_is_after_last_in_tree(
/*===========================*/
	btr_pcur_t*	cursor,	/* in: persistent cursor */
	mtr_t*		mtr)	/* in: mtr */
{
	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
	
	if (btr_page_get_next(btr_pcur_get_page(cursor), mtr) != FIL_NULL) {

		return(FALSE);
	}

	return(page_cur_is_after_last(btr_pcur_get_page_cur(cursor)));
}

/*************************************************************
Moves the persistent cursor to the next record on the same page. */
UNIV_INLINE
void
btr_pcur_move_to_next_on_page(
/*==========================*/
	btr_pcur_t*	cursor,	/* in: persistent cursor */
	mtr_t*		mtr)	/* in: mtr */
{
	UT_NOT_USED(mtr);
	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
	
	page_cur_move_to_next(btr_pcur_get_page_cur(cursor));

	cursor->old_stored = BTR_PCUR_OLD_NOT_STORED;
}

/*************************************************************
Moves the persistent cursor to the previous record on the same page. */
UNIV_INLINE
void
btr_pcur_move_to_prev_on_page(
/*==========================*/
	btr_pcur_t*	cursor,	/* in: persistent cursor */
	mtr_t*		mtr)	/* in: mtr */
{
	UT_NOT_USED(mtr);
	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
	
	page_cur_move_to_prev(btr_pcur_get_page_cur(cursor));

	cursor->old_stored = BTR_PCUR_OLD_NOT_STORED;
}

/*************************************************************
Moves the persistent cursor to the last record on the same page. */
UNIV_INLINE
void
btr_pcur_move_to_last_on_page(
/*==========================*/
	btr_pcur_t*	cursor,	/* in: persistent cursor */
	mtr_t*		mtr)	/* in: mtr */
{
	UT_NOT_USED(mtr);
	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
	
	page_cur_set_after_last(buf_frame_align(btr_pcur_get_rec(cursor)),
				btr_pcur_get_page_cur(cursor));

	cursor->old_stored = BTR_PCUR_OLD_NOT_STORED;
}

/*************************************************************
Moves the persistent cursor to the next user record in the tree. If no user
records are left, the cursor ends up 'after last in tree'. */
UNIV_INLINE
ibool
btr_pcur_move_to_next_user_rec(
/*===========================*/
				/* out: TRUE if the cursor moved forward,
				ending on a user record */
	btr_pcur_t*	cursor,	/* in: persistent cursor; NOTE that the
				function may release the page latch */
	mtr_t*		mtr)	/* in: mtr */